Backyard Orchard News

The Häagen-Dazs Honey Bee Haven, the half-acre bee friendly garden planted last fall next to the Harry H. Laidlaw Jr. Honey Bee Research Facility on Bee Biology Road at the University of California, Davis, is more than just a haven for honey bees.

The grand opening celebration of the garden will take place from 10 a.m. to 2 p.m. on Saturday, Sept. 11, but the bees and other native pollinators are already out there.

And have been for some time.

Native pollinator specialist Robbin Thorp, emeritus professor of entomology at UC Davis, has been monitoring the garden for the past two years--from open field to planted garden.

He's found more than 50 different species of bees representing five families (Andrenidae, Apidae, Colletidae, Halictidae and Megachilidae).

They include the striped sweat bee Halictus ligatus from the family, Halictidae; the yellow-faced bumble bee, Bombus vosnesenskii from the family Apidae; the leafcutter bee, Megachile sp., from the family Megachilidae; and the sunflower bee, Svastra obliqua expurgata from the family Apidae.

YELLOW-FACED bumble bee, Bombus vosnesenskii, is one of three species of bumble bees detected in the Haagen-Dazs Honey Bee Haven. This bumble bee is foraging on a tower of jewels (Echium wildprettii). The haven's five towers of jewels will bloom in the spring. (Photo by Kathy Keatley Garvey)

Leafcutter Bee

ANOTHER BEE detected in the Haagen-Dazs Honey Bee Haven is the leafcutter bee (Megachile sp.) This one is on a rock purslane (Calandrinia grandiflora). (Photo by Kathy Keatley Garvey)

Sunflower Bee

SUNFLOWER BEE, Svastra obliqua expurgata, foraging on a sunflower head. This bee is one of more than 50 species of bees found in the Häagen-Dazs Honey Bee Haven. (Photo by Kathy Keatley Garvey)

Thousand cankers disease, which infects and kills black walnut trees, has spread from the western United States to the eastern United States.

Officials announced Aug. 5 that the disease has been detected in Knox County in east Tennessee. This marks the first detection of the disease east of the Mississippi River.

Previously, the disease was known to eight western states: Arizona, California, New Mexico, Colorado, Idaho, Oregon, Utah and Washington.

And now, Tennessee. It's probably in other states across the Great Plains and east of the Mississippi River, as well.

The disease, caused by the walnut twig beetle (Pityophthorus juglandis) in association with a newly described fungus with the proposed name of Geosmithia morbida), occurs only on walnut species. Eastern black walnut is one of the most susceptible species.

By itself, the walnut twig beetle doesn't present a major problem. Together they wreak havoc.

A pest alert, distributed by the U.S. Forest Service and co-authored by Davis-based researcher Steve Seybold, is sounding the alarm

Seybold, research entomologist with the U.S. Forest Service, Pacific Southwest Research Station, Davis, and a faculty affiliate of the UC Davis Department of Entomology, says the disease symptoms to watch for are branch mortality; numerous small cankers on branches and the main stem of the tree; and the entry and exit holes of the tiny bark beetles. (See news article on presence of the disease in Davis.)

In an attempt to stop the spreading of the disease, the Tennessee Department of Agriculture (TDA) plans to quarantine Knox County to prohibit the movement of firewood and black walnut nursery stock and to limit the movement of black walnut timberland.

The TDA's Division of Forestry estimates that the state has 26 million black walnut trees (both on public and private land). They are valued as high as $1.47 billion.

That's "billion" with a "B."

The losses would be more than monetary, though.

We received a telephone call from a Washington state resident today who is worried--and rightfully so--that his two 100-year-old majestic black walnut trees might contract the disease.

And to think that they could be felled by this duo: a fungus hitching a ride on a tiny walnut twig beetle boring into a tree.

It's a beetle that's smaller than a grain of rice.

Walnut Twig Beetle

TINY walnut twig beetle is cause for concern when a newly described fungus (with the proposed name of Geosmithia morbida), hitches a ride on its back when it bores into black walnut trees. Together they wreak a havoc known as "thousand cankers disease." (Photo by Kathy Keatley Garvey)

Fishback and Laidlaw staff research associate Elizabeth “Liz” Frost paused to watch the butterfly (Papilio rutulus) glide in and out of the flower garden in front of the facility.

Fishback held out his hand. The butterfly obliged and touched down for just a moment.

This year is a good year for Western tiger swallowtails.

There’s an outbreak--or an elevated population--in the area, says noted butterfly expert Arthur Shapiro, professor of evolution and ecology at UC Davis. “I’ve seen as many as 11 a day in Davis recently, and the outbreak ranges from as far west as Vallejo and as far east as Reno.”

This is the second year for elevated populations of the tiger, Shapiro says. The epicenter seems to be Davis.

It doesn't mind being around the 6 million honey bees (from 110 hives) in the apiary at the Laidlaw facility, either.

Spreading Its Wing

WESTERN TIGER SWALLOWTAIL spreads its wings on an agapanthus in front of the Harry H. Laidlaw Jr. Honey Bee Research Facility at UC Davis. (Photo by Kathy Keatley Garvey)

Sip of Nectar

SIP OF NECTAR--The Western tiger swallowtail sips nectar from an agapanthus. (Photo by Kathy Keatley Garvey)

Touch Down!

TOUCH DOWN--The Western tiger swallow tail touches the hand of beekeeper Brian Fishback, president of the Sacramento Area Beekeepers' Association. He was visiting the Harry H. Laidlaw Jr. Honey Bee Research Facility at UC Davis on Friday. (Photo by Kathy Keatley Garvey)

Varroa mites, those blood-sucking little parasites that are major pests of honey bee colonies, can decimate and destroy a colony if left unchecked.

One way that beekeepers monitor their hives for mite infestation is "the sugar shake."

Basically, this involves a quart canning jar equipped with a mesh screen and a lid; and powdered sugar. Beekeepers brush bees from brood comb into a plastic tub or container--being careful, of course, not to brush the queen bee in there, too. They scoop a half of a cup of bees into the jar, add a couple tablespoons of powdered sugar, and then it's time to do "the sugar shake."

They shake the jar vigorously, invert it, and the mites come tumbling out through the mesh screen.

The result: sugar-coated bees and suffocated mites. And all's right with the world. Or "white" with the world.

Beekeepers then count the mites to determine the level of mite infestation and the kind of treatment, if any, that's needed.

Meanwhile, the bees return to their hive where their sisters quickly groom them ("Hey, what happened to you?").

The powdered sugar is harmless. A few minutes later, routine hive activity resumes as if The Great White Shake never happened.

For a brief moment in time, however, the test bees are the insect equivalent of Snow White.

Or the food equivalent of powdered sugar doughnuts or Mexican wedding cookies.

Carpenter bees, which to the uninitiated look like bumble bees, are nice to have around the garden.

Maybe not so nice to have around your untreated patio or fences (as they drill holls in them to make their nests) but just think of them as pollinators, not pests.

As native pollinator specialist Robbin Thorp, emeritus professor of entomology at UC Davis, says: "Carpenter bees are beneficial in that they pollinate flowers in native plant communities and gardens. That far outweighs any damage to wood structures.”

We receive many calls and emails about carpenter bees. Many folks just want to know "what that loud buzz is" or "what's sharing our garden."

The other day we received an email from a carpenter bee enthusiast in Patterson who wanted to know how to keep attracting them to her garden.

Yes!

She inquired: "I had a couple of female bees (Xylocopa varipuncta) visit my garden this summer, but they seemed only interested in Salvia apiana and citrus flowers. Do you have any idea of other flowers that might interest them (I would like to keep them around longer)? Prefer California native plants."

Thorp responded: "Xylocopa varipuncta is a generalist flower visitor and has been recorded from a number of different kinds of flowers. Some natives you might consider include: Asclepias, Salvia, Trichostema, and Wislizenia for nectar; Eschscholzia and Lupinus for pollen.

In our yard, carpenter bees are partial to a variety of native and non-native plants, including salvia, lavender, catmint, rock purslane, purple oregano and African blue basil. They also like the golden day lilies and poppies.